Effects of High Frequency Electroacupuncture on c-fos Expression in the PAG and Hippocampus of Adjuvant Induced Rat Arthritis Pain Model

고빈도 전침차푹이 류마토이드 관절염 통증 모델의 뇌 c-fos 발현에 미치는 영향

Objectives : This study was to investigate the effect of high frequency electroacupuncture at $ST_{36}$ acupuncture point on the Complete Freund's Adjuvant (CFA) induced rat arthritis pain model. Methods : Arthritis was induced by intradermal injection of CFA into base of tail. Experimental groups were divided into 4 groups; Normal, Control and Jok-Samri ($ST_{36}$) and Non-Acupuncture point (NA). Normal group, non-arthritic group, was injected with normal saline，and the others groups were injected CFA. $ST_{36}$ group was treated by 120 Hz electroacupuncture at $ST_{36}$ acupuncture point, and NA group was treated by 120 Hz electroacupuncture at non-acupuncture point. Each groups were evaluated by the change of c-fos positive neurons in periaqueductal gray (PAG) and hippocampus by using an image analyzer and a microscope. Results: - In the PAG region, the number of fos-positive cells in the $ST_{36}$ group ($42.37{\pm}5.08$) were significantly (p<0.05) decreased compared with the control group ($64.56{\pm}6.35$). - In the PAG region, the number of fos-positive cells in the NA group were meaninglessly decreased compared with the control group - In the Cornu Ammonis(CA)l region of hippocampus, the number of fos-positive cells in the $ST_{36}$ group ($7.00{\pm}1.08$) and NA group ($5.56{\pm}2.01$) were significantly (p<0.05) decreased compared with the control group ($13.81{\pm}1.24$). - In the dentate gyrus region of hippocampus, the number of fos- positive cells in the $ST_{36}$ group ($10.75{\pm}0.98$) and NA group ($6.56{\pm}0.78$) were significantly (p$26.45{\pm}1.82$). Conclusions : It is expected that high frequency electroacupuncture can be used a treatment of arthritic pain.